mid-14c., "living together, having dealings with others," also "manner of conducting oneself in the world;" from Old French conversation, from Latin conversationem (nominative conversatio) "act of living with," noun of action from past participle stem of conversari "to live with, keep company with," literally "turn about with," from Latin com- "with" (see com-) + versare, frequentative of vertere (see versus).

Specific sense of "talk" is 1570s. Used as a synonym for "sexual intercourse" from at least 1511, hence criminal conversation, legal term for adultery from late 18c. Related: Conversationalist; conversationist.

mid-14c., originally of religion, from French conversion, from Latin conversionem (nominative conversatio), noun of action from past participle stem of convertere (see convert (v.)). General sense of "transformation" is early 15c. Of buildings, from 1921. Conversion disorder "hysteria" (attested from 1946 but said to have been coined by Freud) was in DSM-IV (1994).

c. 1300, from Old French convertir, from Vulgar Latin *convertire, from Latin convertere "turn around, transform," from com- "together" (see com-) + vertere "to turn" (see versus). Originally in the religious sense. The Latin word is glossed in Old English by gecyrren, from cierran "to turn, return." Related: Converted; converting.

late 14c., from Old French convertible (13c.), from Late Latin convertibilis "changeable," from Latin convertere (see convert (v.)). The noun is recorded from 1610s; meaning "automobile with a fold-down top" is from 1916.

1570s, from Middle French convexe, from Latin convexus "vaulted, arched," past participle of convehere "to bring together," from com- "together," or "thoroughly" (see com-) + vehere "to bring" (see vehicle). Possibly from the idea of vaults carried together to meet at the point of a roof. Related: Convexity. Convex lens is from 1822.

mid-15c., "act of conveying," from convey + -ance. Meaning "document by which something is legally conveyed" is from 1570s; sense "means of transportation" is attested from 1590s. Related: Conveyanced; conveyancing.

mid-15c., "the proving of guilt," from Late Latin convictionem (nominative convictio) "proof, refutation," noun of action from past participle stem of convincere (see convince). Meaning "mental state of being convinced" is from 1690s; that of "firm belief, a belief held as proven" is from 1841.

1811, past participle adjective from verb convolute (1690s), from Latin convolutus, past participle of convolvere (see convolution); or perhaps a back-formation from convolution. French has convoluté (18c.), in form a past participle adjective, without the verb.

early 16c., "the act of guiding or escorting for protection," from convoy (v.), late 14c., from Old French convoier, from Vulgar Latin *conviare, literally "go together on the road" (see convey). The meaning "train of ships or wagons carrying munitions or provisions in wartime under protection of escort" is from c. 1600.

Old English col "not warm" (but usually not as severe as cold), also, of persons, "unperturbed, undemonstrative," from Proto-Germanic *koluz (source also of Middle Dutch coel, Dutch koel, Old High German kuoli, German kühl "cool," Old Norse kala "be cold"), from PIE root *gel- "cold, to freeze" (see cold (adj.)).

Applied since 1728 to large sums of money to give emphasis to amount. Meaning "calmly audacious" is from 1825. Slang use for "fashionable" is 1933, originally African-American vernacular; modern use as a general term of approval is from late 1940s, probably from bop talk and originally in reference to a style of jazz; said to have been popularized in jazz circles by tenor saxophonist Lester Young. Related: Coolly.

name given by Europeans to hired laborers in India and China, c. 1600, from Hindi quli "hired servant," probably from kuli, name of an aboriginal tribe or caste in Gujarat. The name was picked up by the Portuguese, who used it in southern India (where by coincidence kuli in Tamil meant "hire") and in China.